Khawaja achieves his Ashes century dream

It was a special milestone for Usman Khawaja, who has experienced many ups-and-downs throughout his 29 Tests

Usman Khawaja is relieved he finally has an Ashes Test century to savour after a "lot of carry-on" over his debut against England in Sydney seven years ago.

The elegant Pakistan-born left-hander soaked up the acclaim from his home fans after scoring 171 in the final Ashes Test at the Sydney Cricket Ground on Saturday.

Khawaja batted for 515 minutes and faced 381 balls and just missed out on bettering his highest Test score of 174 made against New Zealand in Brisbane in 2015.

It was a special milestone in the career of the 31-year-old, who has experienced many ups-and-downs throughout his 29 Tests.

"It's awesome. The SCG was where I grew up playing cricket for New South Wales and an Ashes century is something I have wanted for a long time and I haven't been able to achieve, so it was very satisfying," he told reporters.

Khawaja savoured the moment he reached his sixth Test century, pointing his bat towards his mother and wife sitting in the stands and getting a long embrace from his batting partner Steve Smith.

"He (Smith) was just telling me to enjoy it. He knows when you get a hundred you're really excited and you want to do lots of things," Khawaja said.

"Your heart's pumping and everything is going. He was just letting me know to just calm down and keep my head back down after everything to go on and make sure I got a big one."